The present invention relates to storage area networks. More particularly, the present invention relates to methods and apparatus to facilitate certain intelligent services with respect to data flowing between a host and a storage device, or the like.
In recent years, the capacity of storage devices has not increased as fast as the demand for storage. Additionally, a host may wish to use multiple storage devices because it needs tiered and heterogeneous storage or because storage management facilities are needed for reasons specific to the storage environment. For example, it may be desirable to use database tables on a fast storage device, and other tables on a slower or less expensive storage device.
In order to solve these storage limitations, the storage area network (SAN) was developed. Generally, a storage area network is a high-speed special-purpose network that interconnects different data storage devices and associated data hosts on behalf of a larger network of users.
In general, a host accesses one or more storage devices so that traffic is flowing between the host and each storage device via an existing infrastructure of switches. In certain situations, it may be useful to provide certain intelligent services to the data traffic flow between a particular host and storage device and it may be preferable to implement such intelligent services on a switch or appliance device that is not in the existing infrastructure or data path that is located between the host and the storage device. For example, the switches that are positioned in a path of a particular host and storage device pair may not have the necessary intelligence, either hardware or software, to implement such a service. Additionally, one may wish to avoid rewiring of the infrastructure between the serviced host and storage device pair so as to not incur significant time, increased complexity, and temporary loss of communication. In another example, it may be desirable to locate a service in a remote location from the data path between a host and storage device pair.
Accordingly, it would be beneficial to provide a mechanism for redirecting the data flow within the SAN to implement these intelligent services. Examples of such intelligent services may include Encryption, Data Migration or SAN Tapping. It would also be desirable to seamlessly provide such redirection with minimal setup by a user.